Local Scale Invariance and Inflation

TL;DR

This paper investigates how local scale invariance influences inflation and cosmological perturbations, highlighting the role of a vector field and gauge freedom in achieving sufficient e-foldings and estimating the scalar power spectrum.

Contribution

It introduces a local scale invariant model with a vector field, analyzing its impact on inflation dynamics and perturbation spectra, which is a novel approach in cosmological inflation studies.

Findings

Local scale invariance provides enough e-foldings for inflation.

The temporal component of the vector field relates to the slow roll parameter.

Scalar perturbation power spectrum is estimated in terms of model parameters.

Abstract

We study the inflation and the cosmological perturbations generated during the inflation in a local scale invariant model. The local scale invariant model introduces a vector field $S_{\mu}$ in this theory. In this paper, for simplicity, we consider the temporal part of the vector field $S_t$. We show that the temporal part is associated with the slow roll parameter of scalar field. Due to local scale invariance, we have a gauge degree of freedom. In a particular gauge, we show that the local scale invariance provides sufficient number of e-foldings for the inflation. Finally, we estimate the power spectrum of scalar perturbation in terms of the parameters of the theory.